字节串是Python3中新增的概念,它不是一个基础类型,可以将字节串与字符串作对比,这样就很好理解,字节串的最小单位是字节、字符串的最小单位是字符,字节串和字符串都是不可变序列。 bytes()的基础语法与bytearray()相同,前者是后者的不可变版本,即bytearray()返回的字节数组中的元素是可变的,可以通过索引去修改...
x = np.array([_ for _ in range(1000)]) This works, but its performance is hidebound by the time it takes for Python to create a list, and for NumPy to convert that list into an array. By contrast, we can do the same thing far more efficiently inside NumPy itself: x = np.ar...
You do not need the more advanced string encoding capabilities ofstringto store a string of bases, but you're still paying for it in performance. Devon Ryan's suggestion ofmaketransis the huge improvement, 10x faster than your naive implementation. Using the same...
Thus, if a data type is astring, the computer might interpret it as the name of a person or city, a greeting and so on. However, if the data is of typeBoolean, the computer will know that it can only have one of two values: true or false. Similarly, the computer will interpret w...
Pickling - is the process whereby a Python object hierarchy is converted into a byte stream, and Unpickling - is the inverse operation, whereby a byte stream
Obviously, a bitArray is much more memory-efficient as it can store 8 values in a single byte, while a single element of a regular array requires multiple bytes to store a single value!A bitArray can be very useful when getting and setting face properties like selected status etc....
Maven is a build automation tool used for Java projects. This blog explains what maven is, its benefits, the project object model (POM), and more.
NumPy can support many different data types, but its primary focus is on numerical data types, such as floating-point numbers, and non-numerical data types, such as text strings, which might see little benefit from NumPy array storage compared to other array storage mechanisms such as Python ...
The buffer protocol is a practical approach in Python that gives access to an object's underlying memory. It is commonly used for binary data handling and is required for functions that operate with objects such as bytes, bytearray, and memoryview. However, Python code could only explicitly che...
a,b,c,d=struct.unpack('5s6sif',bytes) '5s6sif'这个叫做fmt,就是格式化字符串,由数字加字符构成,5s表示占5个字符的字符串,2i,表示2个整数等等,下面是可用的字符及类型,ctype表示可以与python中的类型一一对应。 注意:二进制文件处理时会碰到的问题 ...